How is ureteropelvic (UPJ) junction obstruction diagnosed before and after birth?
- An ultrasound exam before a baby is born can show a UPJ obstruction. As urine gets backed up due to blockage, the kidney swells beyond its normal size, a condition known as hydronephrosis.
- Once the baby is born, tests that measure how well urine is being produced and drained include:
- Blood samples and urine samples such as blood urea nitrogen (BUN) and creatinine tests provide clues on how well the kidneys are filtering the blood.
- An intravenous pyelogram (IVP) injects a dye into the bloodstream that is then traced by X-ray as it flows through the kidney, renal pelvis, and ureter.
- A nuclear renal scan uses a radioactive substance instead of a dye, and can be traced with a special camera. This shows the functioning of the kidney and how much blockage may be present.
- Computed tomography (CT) and magnetic resonance imaging (MRI) scans can show obstructions in the kidney, as well as the structure of the kidneys, ureters, and bladder.